Arcesium, a spinoff of DE Shaw, has outgrown the space it shares with the investment and technology firm on the fifth floor of Minskoff Equities’ 1166 Sixth Ave. Arcesium just signed a lease for 39,075 square feet all its own on the tower’s fourth floor.

The 1.7 million-square-foot tower has about 120,000 square feet of space on the market via JLL. Minskoff is putting in capital improvements designed by Gensler architects to include a new lobby where signature art works by Roy Lichtenstein and others will be displayed.